1. Field of the Invention
The present invention relates to a silver halide photographic light-sensitive material containing a light-sensitive silver halide emulsion, a dye-forming coupler, and a reducing agent for color formation and, more particularly, to a silver halide photographic light-sensitive material by which image formation is possible by performing essentially only alkali bath processing.
The present invention also relates to a silver halide color photographic light-sensitive material which has a high sensitivity and a high storage stability, which can be rapidly processed, and by which the environmental load and the waste can be reduced.
2. Description of the Related Art
Generally, image formation of a silver halide color photographic light-sensitive material is performed through a color development step and a silver removing step. In the color development step, exposed silver halide grains are developed (reduced) by an aromatic primary amine developing agent, and a color image is obtained by the reaction between the oxidation product of the developing agent and a coupler.
In color paper processing, for example, development is performed in an alkali bath containing 4-amino-N-ethyl-N-(.beta.-methanesulfonamidoethyl)-aniline sulfate as the aromatic primary amine developing agent.
On the other hand, black-and-white photographic light-sensitive material using a silver image is developed in an alkali bath containing hydroquinone as the developing agent and ascorbic acid.
When these common color developing agents are used in the form of alkali solutions, they are air-oxidized and significantly deteriorated. Therefore, large amounts of preservatives and replenishers are used to maintain the solution compositions and the photographic properties.
Recently, in this field of art it is being desired to reduce the environmental load and the waste and to reuse the waste. Accordingly, attempts are being made to greatly reduce the processing chemicals and the replenishers of developers.
In maintaining the photographic properties in both continuous processing and intermittent processing, however, although the amount of replenishers are reduced, the processing chemicals in the replenishers are thickened. Presently, therefore, the processing chemicals are not reduced. Also, reducing the replenishers poses another problem in that stains and variations in the photographic properties are significantly increased by the accumulated components.
As an effective means for reducing the processing chemicals and the replenishers, it is possible to incorporate a color developing agent or its precursor into a photographic light-sensitive material. This means is described in, e.g., U.S. Pat. Nos. 2,507,114, 3,764,328, and 4,060,418, and Jpn. Pat. Appln. KOKAI Publication (hereinafter referred to as JP-A) 56-6235 and 58-192031. Unfortunately, these aromatic primary amines and their precursors are unstable and therefore have the drawback that stains are produced when unprocessed light-sensitive materials are stored for long periods of time or color-developed.
In addition to the color development methods described above, there are methods described in, e.g., European Patent (hereinafter referred to as EP) 0545491A1 and EP 0565165A1 in which a sulfonylhydrazine compound is incorporated into a light-sensitive layer. However, no satisfactory color density can be obtained when color development is performed even with the use of this sulfonylhydrazine compound. Also, when a two-equivalent coupler is used, this sulfonylhydrazine compound generates almost no color. When compared to four-equivalent couplers, two-equivalent couplers have the advantages that stains resulting from a coupler can be reduced, the activity of a coupler can be easily adjusted, and various functions can be imparted to a split-off group. Accordingly, the development of a technique which makes the best use of these advantages has been desired.
As a means for solving the above problem, a method is developed by which a carbamoylhydrazine compound which generates colors together with a two-equivalent coupler is incorporated into a light-sensitive layer as a reducing agent for color formation.
Unfortunately, to obtain color images by essentially processing a light-sensitive material with an alkali solution, the reducing agent for color formation described above is contained in the light-sensitive material. Especially when an auxiliary developing agent is additionally contained, the influence of these components significantly decreases the sensitivity of a light-sensitive silver halide emulsion and degrades the storage stability of the light-sensitive material. Therefore, some improvements have been desired and the development of proper stabilizers and silver halide emulsions have been eagerly waited for.